Feeding apparatus for analyzer



J. E. LAWVER I 2,924,488

FEEDING APPARATUS FOR ANALYZER Filed May 14, 1958 4 Sheets-Sheet l PIE.1

Feb. 9, 1960 J. E. L AWVER 2,924,488

FEEDING APPARATUS FOR ANALYZER Filed May 14, 1958 4 Sheets-Sheet 2 @W AM Feb. 9, 1960 J. E. LAWVER FEEDING APPARATUS FOR ANALYZER 4Sheets-Sheet 3 Filed May 14, 1958 ab. 9, 1960 J. E. LAWYER 2,924,488

FEEDING APPARATUS FOR ANALYZER Filed ma 14, .1958 4 Sheets-Sheet 4United States FEEDING APPARATUS FOR ANALYZER Application May 14, 1958,Serial No. 735,297

4 Claims. (Cl. 302-36) The present invention generally relates to afeeding apparatus for an analyzer. The invention moreparticularly'relates to an apparatus for continuously introducing finelydivided material to an X-rayapparatus so that a continuous analysis ofthe material may be made.

The desirability of an accurate and economical method of control "forlarge scale chemical and metallurgical processes. is self-evident.During the past few years, some industries have applied X-rayfluorescent analysis to plant control. 7 v

The earliest practical concepts of X-ray spectroscopy as an analyticaltool were illustratedflby Barkla (1908- 1911); Barkla had found that onradiationywith X-rays thedifierent elements emitted secondary X-rayswhich were characteristic of the elements. Since that time, the methodhas "become quite popular in industrial applicationsduet o its-accuracy,simplicity of sample preparation,and'therapidity of analysis.

- The present invention,'however, is not concerned with the method of orapparatus for X-ray analysis'per se, but it is directed to an apparatusfor introducing finely divided material to {an X-ray apparatus so thatan analysis of thernaterial may be made.

Heretofor'e,-"-nrost-of-tl1e industrial applications of X- rayfiuoreseent'analysis to plant .control have been on 'ahatchz-test basis.A continuous method of'analysis and control is, "however, superior tobatch testing methods. For exampie, in a chemical .or'metallurgicalprocess plant'where' moving beds of solids'and streams of {liquids areencountered, in 'order to achieve efficient automation oron-stream'con'tinuous control of-the plant, alcontiuuous method ofanalysis "must be used. The use of X-ray analyzing apparatus in controlinstrumentation has proven quite efie'ctiveyhowever, as hereinbefore setforth, inoifderto achieve efficient automation, acontinuousme'tho'dcfanalysis-must be used. The X-ray analysis methodperse is readily'suitablefor-use in continuous control methods and thepresent invention is specifically directed to -continuously introducingmaterial to be analyzed to X-ray apparatus. It is, accordingly, anobject of theprese'nt invention to provide a feeding apparatusforcontinuously introducing material to an analyzer so that a"continuous analysis of the material may be made.

Ano'theno'bject ofthe invention isto provide a=feedingapparatfl'siorcontinuously introducing finely divided solid materialtoan 'K-ray. apparatus for analysis, which feeding apparatus isareddilyadapted for use with existing x-ray analysis apparatus. V Furtherobje'cts and advantages'ot the present inventiomwilhbe apparent from'the'following description and accompanying drawings which-illustrateone "form of the invention. a V In the drawings:

wFigure lriis a plan -view of a fee'cling apparatusembodyingtvariousfeaturesof this invention; I

Figure 2 is a side elevational view of the feeding apparatus shown inFigure 1;

face of the turntable.

Figure 3 is a rear elevational view of the feeding apparatus shown inFigure 1;

Figure 4=is a fragmentary sectional view of the feeding apparatus takenalong line 4-4 of Figure 3;

Figure 5 is'a fragmentary sectional view taken along line 5-.5 of Figure4; and,

Figure 6 is a fragmentary sectional view of a leveling blade of thefeeding apparatus taken along line 6-6 of Figure l.

The present invention provides an apparatus for introducing dividedsolid materials to an X-ray apparatus so that an analysis of thematerialmay be made. Examples of such materials are powders, crystals,granules, etc. such as occur in finely divided ores, for example, potashore, phosphate ore, etc. The material must be relatively finely dividedso that it may be readily handled in the apparatus. Large chunks wouldnecessarily have to be ground before the material could be used in theapparatus.

The feeding apparatus includes a turntable rotatable aboutasubstantially vertical axis and means for rotating the turntable aboutthe vertical axis. A circular groove is provided in an upwardly facingsurface of the turntable. The circular groove is concentric with thevertical axis of'rotation of the turntable. The groove is provided tohold the material to be analyzed on the turntable.

The apparatus provides a delivery means for delivering material to beanalyzed to the circular groove. This deliverymeans delivers thematerial .to the groove as the turntable rotates, in an amount greaterthan needed to fill "the groove. In other words, the material issupplied to the groove at a rate, such .that the material overfills ormounds the groove. This type of delivery means is provided to insurethat the groove is filled.

I The apparatus also provides means for leveling the material in thegroove. In order to obtain an accurate analysis of'the materiahit ispreferred that the material be supplied to the X-ray apparatus as asubstantially level surface which has a constant elevation relative tothe X-ray apparatus. Since the feeding mechanism overfills the groove ina manner such that the surface is uneven, a leveling means ispreferably'provided to level the material. 1

' The apparatus also supplies ameans for removing the material from thegroove after it is analyzed. This removingv means operates continuouslyas the turntable operates so that a clean portion of the groove may bepresented to the delivery means for delivery of another sample to beanalyzed. The use of the apparatus for analyzing granular materialsmakes possible continuous and rapid analysis. The use also makespossible the automatic control of various process streams which aifector are aifected by the composition of the material analyzed.

Anembodiment of the apparatus of the present invention is shown inthe'drawings and is described in the following paragraphs. While theapparatus shown is specifically adapted to delivering material to anX-ray apparatus, it will be understood that the apparatus may be usedfordelivering material to other types of analyzing apparatus.

As will hereinafter become apparent, the feeding apparatus 9 shown inthe drawing includes, generally, a circular or disc-shaped turntable 11positioned so as to rotate about its axis which is vertical. A means .13is provided for rotating the turntable 11 at a predetermined Constantspeed and in the predetermined direction illustrated by the arrow A'inFigures 1, 2 and 3. The material to be analyzed is placed in a deliverymeans 15 which feeds the material into a circular groove 17 in the uppersur- After the material in the groove leaves the position under thedelivery means, the material through a key and slot connection 51.

is acted upon by a leveling means 19 which levels the material so thatits upper surface is in the same plane as the upper edges of the groove17. As the turntable continues to rotate, the material in the grooveafter being leveled passes through an analysis station represented onthe drawings by the X-ray analyzing section 21 After being analyzed thematerial must be removed from the groove so that another portion ofmaterial may be placed in the groove and to accomplish this a novelmeans 23 for removing the material is provided.

Referring now more particularly to the drawings, the specific feedingapparatus illustrated, embodies various of the features of the inventionand, as has been pointed out, is particularly adapted to the feeding offinely divided material, such as a potash ore, to an X-ray analyzer. Theillustrated apparatus has a support frame 25 which includes a heavy baseplatform 27 having a vertical structural suport 29 which supports themeans 23 for removing material from the groove 17 and a verticalstructural support 31 which supports the delivery means 15.

The means 13 provided for rotating the turntable is a motor and gearhead unit 13 which includes an electric motor 33 and a gear speedreducer and direction changer 35 which are drivingly interconnected. Themotor and gear head unit 13 is secured to the base platform 27 by nutsand bolts 37. The motor 33 is connected to a source of electrical energy(not shown) through suitable electrical leads and switch 39 (Fig. 3)which is secured in a switch box 41. The switch box 41 is secured to thevertical structural member 31. The motor and gear head unit 13illustrated is of the constant speed type, that is the rotational speedof the output shaft 43 is a predetermined constant. Motor and gear headunits in which the speed of the output shaft is adjustable may, however,be used.

The turntable 11 illustrated includes a circular disc member 45 whichhas a substantially flat upper surface 47; The central portion of thedisc member 45 is bolted by nuts and bolts 46 to a flanged fitting 49and the i4 is preferred to provide a hopper to insure relatively uniformflow of material into the groove.

The lower section of the sides of the hopper slope inwardly toward anopening 55. in the bottom of the hopper. The opening 55 is positioneddirectly above the groove 17. The opening is of a suflicient size tooverfill the groove 17 as the turntable rotates. In order to insure arelatively uniform flow of material through the hopper 53 and out of theopening 55 into the groove 17, it is preferable that the hopper 53 bevibrated. In the illustrated embodiment, two vibrators 57 and 59 areprovided; These vibrators are firmly attached to the hopper. Thevibrators illustrated are electrically operated and they are accordinglyconnected to a suitable source of electrical energy (not shown). Thevibrators illustrated operate at a relatively low voltage as compared tothe voltage necessary to operate the motor 33. Since a common source ofelectrical energy is usually used, a step-down transformer 61 isprovided in the circuit so as to supply a lower voltage to thevibrators. The transformer 61 is attached to the vertical structuralmember 31. The hopper 53 is also secured to this vertical structuralmember 31 by nuts and bolts 65. An electrical switch 63 in the switchbox 41 is in the electrical circuit to the transformer.

flanged fitting in turn is mounted on the output shaft 43 It isimportant that the sample of material to be analyzed be delivered tothe'aualyzing section 21 of the X-ray apparatus (not shown) in a mannerthat the elevation of the upper surface of the sample be substantiallyconstant relative to the analyzing section. This is readily accomplishedin the illustrated apparatus by mounting the turntable 11 on the outputshaft 43 carefully so that the plane of the upper surface 47 of theturntable is perpendicular to the vertical axis of rotation of theoutput shaft 43.

The circular disc member-45 of the turntable 11 has the circular groove17 in the upper surface 47. As is illustrated in Figures 4 and 6, thecross section of the groove, taken cross wise to the groove, is aninverted isosceles trapezoid. This cross-sectional configuration of r ithe groove is preferred since it has been found that when the materialisin such a groove the surface may readily be leveled or smoothened. Thecircular groove is concentric with the axis of rotation of the turntableand is positioned adjacent to the outer periphery. It is to .beunderstood that the groove 17 may have configurations other than thatillustrated'in the drawings. The depth of the groove, however, should beat least twice the average particle size of the material to be analyzed.If the groove is of less depth, difliculty is often experienced inleveling the material and in analyzing the material.

The material to be analyzed is delivered to the groove 17 by thedelivery means 15, which is peripherally spaced A bottom closing member67 is provided on the hopper 53 so as to stop the flow of material outof the hopper 53 through the opening 55 when desired. The bottom closingmember includes a substantially square plate 69 which is somewhat largerthan the opening 55 so as to be capable of closing the opening 55 whenit is positioned against the opening as is indicated by the solid linesin Figure 5. The plate 69 is attached to an elongated lever 71 which ispivotally mounted on a bolt 73 secured in a side of the hopper 53. Thelever 71 may be pivoted about the bolt 73 so as to attain the positionindicated by the dotted lines in Figure 5, in which position theplate 69is removed from the opening 55 so that material in the hopper 53 mayflow out of the opening.

As is illustrated in Figures 4 and 5, the delivery means 15 overfillsthe groove. It is important, however, that'the upper surface of thematerial in the groove be substan: tially smooth and level and there is,therefore, provided the leveling means 19 overlying the groove andmounted intermediate the delivery means 15 and the analyzing section 21for accomplishing this. The leveling means 19 provides a leveling edgeand as illustrated includes a pair of adjustable wiping blades or knives75 and 77. Each of these blades, 75 and 77, is mounted on a bracket 79and 81 respectively. The upper edge of each of the blades, 75 and 77,has a pair of slots, 80 and 82 respectively, therein and screws 83 inthese slots hold the blade securely to the respective bracket. The slots80 and 82 permit the blades to be adjusted up or down so as to beengageable with material in the groove to achieve the desiredsmootheningefiect on the top surface of the material in the groove. Eachof the brackets, 79 and 81, is mounted on a short rod, 85 and 87respectively, which extends horizontally and radially from a hub 89.Each of the brackets 79 and 81 and the respective rods, 85 and 87,

from the analyzing section 21. The delivery means 15 is pivotallyadjustable about the longitudinal axis of each respective rod so as topermit the adjustment of the slope of the blades 75 and 77.

The hub 89 is mounted on a lower portion of a rod 91 which depends fromand is secured to the hopper 53. The hub and its attachments areadjustable up and down on the rod 91. A set screw 93 (Fig. 2) extendsthrough the hub 89 to the rod 91 so as to lock the hub in position onthe rod. In the illustrated embodiment, two leveling blades areillustrated. It is to be understood, however, that one or more may beused. The number of leveling blades used depends to some extent upon thephysical characteristics of the material in the groove 17. The blades 75and 77 are adjusted so that they are slightly touching the upper surface47 of the turntable 45 (Fig. 6).

the dog house 95 is not resting on "the turntable but i it is "supportedby the rest of the X-ray apparatus (not shown) to be positioned at apredetermined elevationfor cooperation with the turntable. The"doghousefis illustrate'd so that its position relative]to;the.turntablemaylbe rrtore easily understood. Inoperation, withathe fidog house 95supported on the X-rayapparatus, the turntable passes through an opening97'.in the sides 'of-th'e dog House. (v

The dog house 95 also has a circular opening 99 which accommodates the"X-ray'tube (not illustrated) of the X-ray apparatus. In a side of thedog house adjacent to the Wall in which the opening 99 is positioned, aneck 101 with an-opening 103- (Fig. 1) is attachedfl-This neck andopening are adaptedto fit 'the collinrator fofthe X-r'ay apparatus. Inoperation, the l dog hous'e' 95-*-is rotten filled'with an inertgas-such as'helium orliydro'gen and in order to prevent the gas fromrapidly escaping through the opening 97 through which the turntablepasses, adjustable scrapers 105 are positioned and screwed on the doghouse about the opening 97 and these are adjusted so that they are insliding contact with the turntable 11, thereby reducing any openingbetween the dog house and the turntable to a minimum. As hereinbeforestated, the design of the dog house or any of the remainder of the X-rayapparatus forms no part of the present invention and the dog house isillustrated merely to show its position relative to the other members ofthe feeding apparatus 9.

After the material in the groove 17 is analyzed, it is removed from thegroove by the means 23. The novel means 23 illustrated is mountedintermediate the analyzing section 21 and the delivery means 15, andincludes a centrifugal blower 107 which is driven by an electric motor169. The blower 107 has a depending suction nozzle 111 connected theretoand the lower end 112 (Fig. 2) of the suction nozzle terminates adjacentto turntable 11 and directly above the groove 17. In operation, as theturntable revolves and carries the material in the groove under thesuction nozzle, the material is sucked up out of the groove through thesuction nozzle 111 and is blown out through the discharge nozzle 113thereby thoroughly cleaning out the groove 17. The groove is thereforeprepared for another filling as it passes beneath the delivery means 15.

A horizontal support member 115 extends from an upper portion of thevertical support 29 and is welded thereto. The other end of thehorizontal support member 115 is attached to a convex formed platemember 117 into which the motor 109 is nested. In order to hold themotor 109 securely to the plate member 117, a pair of ring clamps 119 isprovided. The motor 109 is connected to a suitable source of electricaleneregy (not shown) in a conventional manner and a switch 121 in theswitch box 41 is provided in the circuit.

In one commercial embodiment of the apparatus which has been described,the turntable 11 had a diameter of 24 inches. The motor 33 was ofone-eighth horsepower and rotated the turntable at 1%, r.p.m.' Theblower motor 109 was horsepower. Using this apparatus, a continuousanalysis of material was made using X-ray fluorescent apparatus foranalysis. The use of this apparatus understood that such details areillustrative only and are not by way of limitation. Other modificationsand equivalents. ofl t he inveritionwill gbe appa rentto those skilledin the' artgfromthe foregoingdescript- 9n. I Haying now .fully describedand. llustrated the invention, what is desired tobe securedand-claimedby Letters Patent -lSrs et forth in the appendedclaims.

1. lnjapparatus for deliveripg divided solid material for analysis thecombination of meansfor mounting analyzing apparatus at a. predeterminedelevation for analyzing divided solid material passed through anyanalysis station, a turntable, rotatable about a substantially verti-0511 axis and having apperipher al; portion of said turntable extendingthrough said analysis station means for rotating said turntableabout-said vertical axisin a predeterrnined direction, said turntablehaving an upwardly "facing :surface with an *annular; groove formedtherein concentric with said vertical -axis andqdisposed to pass throughsaid analysis station as said-turntable rotates, materiahdelivery. meanshavingan outlet disposed above .groov eand peripherallyaspa'ced fromsaidanalysis ion to dischargeafiow of divijdedsolid material into groove inan amount greater than-thatneeded to fill s d., groove, :-leveling"means mounted --intermediate said analysisfstation'and-said-outletand-providing a leveling edge overlying said groove-and engageable withmaterial 1,11 e to produce a substantially level upper surface at apredetermined elevation relative to said mounting means, and materialremoval means mounted intermediate said outlet and said analysis stationto withdraw material from the groove after passing through said analysisstation and prepare the groove for introduction of further divided solidmaterial from said outlet as said turntable rotates.

2. In apparatus for delivering divided solid material for analysis thecombination of means for mounting analyzing apparatus at a predeterminedelevation for analyzing divided solid material passed through ananalysis station, a turntable rotatable about a substantially verticalaxis and having a peripheral portion of said turntable extending throughsaid analysis station, means for rotating said turntable about saidvertical axis in a predetermined direction and at a substantiallyconstant speed, said turntable having an upwardly facing surface with anannular groove formed therein concentric with said vertical axis anddisposed to pass through said analysis station as said turntablerotates, material delivery means having an outlet disposed above saidgroove and peripherally spaced from said analysis station tocontinuously discharge a flow of divided solid material into said groovein an amount greater than that needed to fill said groove, levelingmeans mounted intermediate said analysis station and said outlet andproviding a leveling edge overlying said groove and engageable withmaterial in said groove to produce a substantially level upper surfaceat a predetermined elevation relative to said mounting means, andmaterial removal means mounted intermediate said outlet and saidanalysis station to continuously withdraw material from the groove afterpassing through said analysis station and prepare the groove forintroduction of further divided solid material from said outlet as saidturntable rotates. Y

3. In apparatus for delivering divided solid material for anlysis thecombination of means for mounting analyzing apparatus at a predeterminedelevation for analyzing divided solid material passed through ananalysis station, a turntable rotatable about a substantially verticalaxis and having a peripheral portion of said tumtable extending throughsaid analysis station, means for rotating said turntable about saidvertical axis in a predetermined direction and at a substantiallyconstant speed, said turntable having an upwardly facing surface with anannular groove formed therein concentric with said vertical axis anddisposed to pass through said analysis station as said turntablerotates, a hopper having an outlet disposed above said groove andperipherally edge overlying" said'groove andengageable with material insaid groove to produce a substantially level upper surface atapredetermined elevation relative to said'mounting means, andvacuummeans mounted intermediate said outlet and said analysis stationto continuously withdraw material from the groove after passing throughsaid analysis station and prepare the groove for introduction of furtherdivided solid material from said outlet as said turntable rotates.

4. In apparatus for delivering divided solid material for analysis thecombination ofmeans for mounting analyzing apparatus at' 'apredetermined elevation for analyzing divided solid material passedthrough an analysis station, a turntable rotatable about a substantiallyvertical axis and having a peripheral portion of said turntableextendingthrough said analysis station, means for rotating saidturntable about said vertical axis in a predetermined direction and at asubstantially constant speed, said turntable having an upwardly facingsurface with an annular'groove formed therein concentric with saidvertical axis and disposed to pass through said analysis station as saidturntable rotates, said groove having an inverted isosceles trapezoidcross section and having a depth of at least twice the average particlesize of the material to be analyzed, a vibrating hopper having 'an'outlet disposed above saidrgroove and peripherally lspaced from said'analysis station to continuously discha'r'ge a flow'of dividedsolid'material into. said groove in an amount greater than that neededto fill said groove at least one scraper blade mounted intermediate saidanalysis station and said outlet and providing a leveling edge overlyingsaid groove and engageable with material in said groove to produce asubstantially level upper sur} face at a predetermined elevationrelative to said mounting means, and an electric motor driven suctionmeans mounted intermediate said outlet and said analysis station tocontinuously withdraw material from the groove after passing throughsaid' analysis station and, prepare the groove for introduction offurther divided solid mate'- rial from said outlet as said turntablerotates.

References Cited in the file of this patent UNITED STATES PATENTS2,522,203 Williams Sept. 12,

